api-radar

name	api-radar
description	Analyzes REST API endpoints in any GitHub repository (read-only) and generates structured API documentation as Endpoint Reference Cards. Supports Django, FastAPI, Express, NestJS, Spring and more. Find endpoints by path, keyword, or natural language — or analyze API changes in PRs, commits, and branches.
metadata	{"author":"divlook"}

API Radar

Analyzes API endpoints in a GitHub repository read-only and produces reference documentation. Never creates, modifies, or deletes any code, file, branch, or PR — only analysis and documentation.

Input Format

Users make requests in the following format:

• [repo] [query]

repo is one of:

• owner/repo (recommended)
• GitHub repository URL (e.g. https://github.com/example-owner/example-repo)
• alias (if registered in references/repo-aliases.md)

query is one of:

• API path (e.g. /v1/users/{user_id})
• keyword
• description (in any language)
• PR / commit / branch reference

Input examples:

Type	Example	Description
API path	example-owner/example-repo /companies/{company_id}/users	When the exact path is known
Keyword	example-owner/example-repo partner	When part of an endpoint/identifier is known
Description	example-owner/example-repo file upload API	When only the functionality is known
Repo URL	https://github.com/example-owner/example-repo /v1/health	Specifying repo by URL
PR number	example-owner/example-repo PR#123	Analyze API changes in a specific PR
Commit	example-owner/example-repo commit 1a2b3c4	Analyze based on a specific commit
Branch	example-owner/example-repo branch feature/file-upload	Analyze based on a specific branch
Alias	my-api /v1/health	Specify repo by alias

If the repo cannot be identified from the input (e.g. missing repo, typo, URL parse failure), always ask the user for clarification.

Core Workflow

Step 0: Determine Search Mode

Check whether the input contains a PR, commit, or branch keyword.

Keyword	Search Method
PR #number, PR keyword	Retrieve PR metadata/changes via gh
commit keyword	Retrieve commit via gh
branch name	Retrieve branch/files via gh
Other	String-based search (best-effort)

GitHub CLI Auth Check

Before analyzing PR/commit/branch, verify authentication status:

gh auth status

If not authenticated, output the following (do not perform authentication yourself):

⚠️ GitHub CLI authentication required.
Please run 'gh auth login' in your terminal to complete authentication.

Step 1: Search Endpoints

Default Search (best-effort)

Search strategy by input type:

[When the API path is known]

• Query: @router.get("/companies") or path("companies/")
• Find endpoint code directly with the exact path

[When only a keyword is known]

• Query: partner PartnerViewSet partner_router
• Explore candidate ViewSets, Routers, and API files

[When only a description is known]

• 1st search: original keywords
• 2nd search: English translation / alternative terms
• 3rd search: domain-specific terminology (e.g. login, payment, upload)
• Present a list of related endpoints first, then do a detailed analysis after the user selects

[When multiple results are found]

• Present related APIs in a table
• Guide the user to select which API to analyze

Example output:

#	Path	Method	Description
1	/files	POST	Upload a file
2	/files/{id}	GET	Retrieve file metadata
3	/files/{id}/download	GET	Download file content

Please select the API number to analyze.

PR/Commit/Branch Search (GitHub CLI)

[When PR number is known]

gh pr view {PR_NUMBER} --repo {owner}/{repo}
gh pr view {PR_NUMBER} --repo {owner}/{repo} --json files,title,body,author
gh pr diff {PR_NUMBER} --repo {owner}/{repo}

[PR keyword search]

gh pr list --repo {owner}/{repo} --search "{keyword}" --state open --limit 10
gh pr list --repo {owner}/{repo} --search "{keyword}" --state merged --limit 10

Example output:

#	PR	Title	Author	Status
1	#456	feat: add file upload API	@developer	Open
2	#423	fix: file size validation error	@developer	Merged

Please select the PR number to analyze.

[Commit message search]

gh search commits --repo {owner}/{repo} "{keyword}" --limit 10

[Analyze specific branch code]

gh api repos/{owner}/{repo}/contents/{file_path}?ref={branch_name} --jq '.content'

Note:

• .content is base64-encoded and must be decoded.
• On macOS use base64 -D; on GNU systems base64 -d may work.
• When unsure, use python3:

python3 - <<'PY'
import base64, sys
print(base64.b64decode(sys.stdin.read()).decode('utf-8', errors='replace'))
PY

Comparing branch with default branch (list of changed files):

gh repo view --repo {owner}/{repo} --json defaultBranchRef --jq '.defaultBranchRef.name'
gh api repos/{owner}/{repo}/compare/{defaultBranch}...{branch} --jq '.files[].filename'

Step 2: Repo Profiling

For each request, quickly identify the backend framework/routing/schema hints in the repository on a best-effort basis, then maintain the same analysis flow (search → auth/permission → errors → Endpoint Card documentation).

Refer to references/framework-detection.md for framework-specific detection hints.

Do not stop work even if the framework/routing/schema cannot be confirmed.

• Continue with Endpoint Card documentation using the same template/flow.
• Leave uncertain or unconfirmed items in the #### Uncertainties section of the output, along with evidence (search terms / candidate file paths / reasoning).

Step 3: Extract Auth/Permission

Common authentication methods (project-specific — check actual implementation):

• API Key (e.g. X-API-Key: {key} header)
• JWT Bearer token (e.g. Authorization: Bearer {token})
• Session / Cookie-based auth

Token payload and session claims vary by project — extract only observed fields (e.g. user_id, role, scope).

Permission info extraction (varies by framework/project):

• Decorator-based: e.g. @require_permissions("read:files"), @permission_required("admin")
• Middleware-based: e.g. role/scope checks in auth middleware
• Inline checks: e.g. if not user.has_perm("app.change_file"): raise PermissionDenied

Record only observed permission patterns — note the source file and mechanism.

Step 4: Analyze Errors

Error response formats vary by API/project, so do not assume a "common format".

Rules (Observed-first):

• Only describe things actually observed from status codes/exception classes/handlers/common processing (e.g. middleware, exception filter/handler) as Errors (Observed).
• Since error body/field names/code schemes vary by project, only record actually confirmed fields/values.
• Leave unobservable/uncertain items as unknown, with evidence (search terms used + candidate file paths).

Information extractable from exception/error definitions (field names vary by project):

• status_code: HTTP status code (400, 401, 403, 404, etc.)
• error_code: value corresponding to business error code (e.g. error_code, code, errorCode, etc.)
• message: value corresponding to user message (e.g. message, error_message, detail, etc.)

Step 5: Generate Output

Document the analysis result according to the output template.

• General API analysis: references/endpoint-card-template.md
• PR analysis: references/pr-analysis-template.md

Constraints

Allowed Commands Only

Command	Purpose
gh auth status	Check GitHub CLI authentication status
gh repo view	View repository info
gh pr view	View PR details
gh pr diff	View PR changes
gh pr list	Search PR list
gh search commits	Search commit messages
gh api	Query GitHub API (GET only)
git status	Check repository status
git diff	Compare changes
git log	View commit history
base64	Base64 decoding
python / python3	Data processing (decoding, etc.)
jq	JSON parsing

Denied Patterns

The following commands are never used:

Pattern	Reason
gh api --method / gh api -X	No write API calls
gh auth login	No auth changes
gh repo clone	No repository cloning
git commit / git push	No code changes
git checkout / git switch	No branch switching
curl / wget	No external HTTP requests
rm / mv / cp	No file manipulation

Principles

• Do not modify or create code
• Clearly indicate uncertain parts in the analysis result
• Ask the user for additional information if the endpoint cannot be found in the repository
• Do not output sensitive information (API keys, passwords, etc.)
• Guide the user if GitHub CLI authentication is required

Resources

references/

Reference	When to Use
references/repo-aliases.md	Repository alias mapping — when resolving repo from user input
references/endpoint-card-template.md	Endpoint Reference Card output format — for general API analysis output
references/pr-analysis-template.md	PR analysis output format — for PR-based API change analysis output
references/framework-detection.md	Framework-specific routing/schema detection hints — referenced during Repo Profiling

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Source: divlook/agent-skill-api-radar — distributed by TomeVault.